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7th grade · Science · Unit 2 of 14

Circuits & Static

Circuits, conductors and static charge

What your child practices

Complete circuits, series versus parallel wiring, conductors and insulators, adding cell voltages, and static electricity (like and opposite charges, lightning).

New York State Learning Standards learning standard: MS-PS3-6; MS-PS2-3 · energy carried by electric currents in circuits, and the electric forces between charges

How we explain it

Children can open this short lesson before they practice.

  1. Current flows only around a complete, unbroken loop.
  2. A series circuit has one path, so one broken bulb stops them all. A parallel circuit has several paths.
  3. Static charges: like charges push apart, opposite charges pull together.

Example: A parallel circuit has 3 bulbs. One burns out. How many stay lit? In parallel, each bulb has its own path. The other paths are still complete. 3 − 1 = 2. Answer: 2

Circuits & Static in New York

In the New York State Learning Standards, this is unit 2 of 14 in 7th grade Science, after Atoms & Elements and before Ecosystems.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: New York State Education Department (NYSED)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Each cell gives 1.5 V. If 4 cells are connected in series (end to end), what is the total voltage?

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    answer boxV

  2. Question 2

    A series circuit has 5 identical bulbs and a battery. One bulb burns out. How many bulbs stay lit?

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    answer box

  3. Question 3

    Which part of a circuit is the source of electrical energy?

    🔋
    • the battery
    • the bulb
    • the switch
    • the wire

  4. Question 4

    What does a circuit need for current to flow?

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    • A switch that is left open
    • A complete, unbroken loop from the energy source and back
    • Two batteries touching each other
    • Just a bulb and one wire

  5. Question 5

    Why are the lights in a house wired in parallel?

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    • So one switch turns off every light at once
    • It makes every bulb dimmer to save energy
    • Parallel circuits need no power source
    • Each light can work even if another is switched off or burns out

  6. Question 6

    In a metal wire, which particles move to carry the electric current?

    • electrons
    • protons
    • whole atoms
    • neutrons

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